Charge forming device



Oct. 18, 1932. w. H. TEETER 1,883,097

CHARGE FORMING DEVICE Filod Aug. 19. 1929 2 Sheets-Sheet l ze i 5 22 ZI/z'lfond IY JeeZer Oct. 18, 1932. w J R v 1,883,097

CHARGE FORMING DEVICE Filed Aug. 19. 1929 2 Sheets-Sheet 2 ZMAM Patented Oct. 18, 1932 PATENT? OFF-ICE WILFORD H. TEE'IER, OF DAYTON, OHIO, ASSIGNOB 'ro DELCO rnonuc'rs coaronarron,

OF DAYTON, OHIO, A CORPORATION OF DELAWARE CHARGE FORMING DEVICE Application filed August 19, 1929. Serial No. 387,009.

This invention relates to charge forming devices for internal combustion engines, and most particularly to that type of charge forming device which comprises a plurality of carburetors,

primary mixture of fuel and air to a plurality of secondary carburetors located adjacent the engine intake ports, where additional air is mixed with the primary mixture before the latter enters the engine cylinders.

A device of this character is disclosed in the copending application of Wilford H. Teeter, Serial N 0. 288,685, filed June 27, 1928, and the present invention is disclosed herein as embodied in a charge forming device having the structure of that disclosed in said application. a

It is the principal object of the present invention to provide improved means for controlling the admission of air to the device whereby a fuel mixture having the desired proportions of fuel and air may be provided. More specifically, it is the object of this invention to provide means for controlling the closing of the secondary air valve by the engine suction in order that the valve may occupy at all times the proper position as determined by the vacuum maintained within the charge forming device.

In devices of this character such as heretofore designed, a valve has been provided to control the admission of .auxiliary air which has been retarded in its opening movements by means of a dashpotr Under certain operating conditions when the suction within the manifold decreases, such auxiliary valve must be moved toward closed position in order to prevent the admission of too much air and consequent leaning of the mixture. According to the present invention, means have been provided comprising an auxiliary piston operated by the manifold vacuum and constructed to operate a lever adapted to return said auxiliary valve toward closed position, a suction passage being provided to communicate the manifold vacuum to said piston.

Further objects and advantages of the present invention will be apparent from the folone for each intake port of the engine, which are adapted to deliver a lowing description, reference being had to the accompanying drawings wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a vertical section through the carburetor unit of a charge forming device em bodying this invention.

Fig. 2 is a horizontal 2-2 of Fig. 1.

Fig. 3 is a fragmentary section on the line 33 of Fig. 1.

Fig. 4 is a fragmentary, vertical section on the line 44 of Fig. 2

Fig. 5 is a plan View of a charge forming device embodying the present invention.

Referring to the drawings and more particularly to .Figs. land 5, the reference numeral indicates the main housing of a. carburetor unit adapted to be attached to an air manifold 11, by a flange 12, which is secured to a cooperating flange 13 in the conventional manner. The manifold has three outlet branches 15, cooperating with the engine intake ports in the usual manner and the outlet ends of these branches form secondary mixing chambers as hereinafter more fully set forth.

The main housing 10, above referred to, has secured to itsbottom wall, a frame in the form of a casting 14,. in any desirable manner. The main housing contains the main air valve, carburetors, throttles and other mechanism later more particularly described, while the frame 14 has formed therein the fuel passages conveying fuel from the float chamber to the primary carburetors, various dashpots for controlling the admission of air and other devices more fully described hereinafter. In addition, the frame 14 provides the top for a constant level sheet metal fuel bowl 16, the upper edge of which fits against a shoulder 18, formed on a projecting flange of the frame 14, the bowl being held tight against the shoulder by a screw 22, screwed into a part of the frame 14, as indicated in Fig. 1. Suitable gaskets may be provided to preventleakage.

Fuel is supplied to the bowl from a fuel section on the line auxiliary air valve, primary supply line (not shown) and a constant level Within the bowl is maintained by a float 24 in the conventional manner. fuel passage 26 is provided to convey fuel from the bowl to the primary carburetors which will be more fully described later. The lower horizontal portion of this passage communicates with a vertical passage 28, formed in a projecting part of the frame 14, as shown in Fig. 3, and a calibrated fuel metering plug 30 admits fuel to the passage 28 at all engine speeds, as indicated in said Fig. 3. All of the fuel supplied to the primary carburetors at all engine speeds up to that corresponding to a vehicular speed of approximately 55 miles per hour on a level, flows through the plug-30 so that said plug regulates the flow of fuel per unit of time at all speeds under that referred to, while additional fuel is admitted to the passage 26 at higher speeds through a fuel inlet 32 controlled by a valve 34, which is normally in a position to close said port, but is adapted to be lifted by means-not. shown herein, at approximately the speed above referred to, permitting a flow of fuel through the port 32 to augment the fuel supplied through the plug 30. The specific mechanism above described, forms no part of this invention, and reference may be had to the above-mentioned application for a more complete disclosure of this mechanism. 1

The fuel passage 26 at its upper end communicates with a horizontal fuel channel 36, formed in the upper face of the frame 14 and An angular shown in Figs. 1 and 3. This channel com-.

municates with three calibrated plugs 38, screwed into the lower face of the main housing and each of which supplies fuel to one of the three vertical passages 40, bored in the 'wall of the main housing, as shown in Figs. 1 and 3. Each of the passages 40 supplies fuel to one of three parallel primary mixture passages, indicated in their entirety by the reference numeral 42. After the valve 34 is opened as previously described, to render the port 32 effective, the calibrated plugs 38 meter or regulate the total quantity of fuel supplied per unit of time to the primary carburetors. 1

Each of the primary carburetors comprises an angular mixture passage having a horizontal outlet portion 44 and a vertical inlet portion 46. These passages are in substantially parallel planes and are bored in the bottom wall of the main housing. The vertical portions 46 of the mixture passages communicate with a main air chamber 48, formed in the main housing 10 and will be more fully described later. All of the air flowing through the mixture passages at all engine speeds is supplied from said main air chamher, in which the suction at any engine speed is a static suction determined by the spring ply fuel.

held main air valve which. controls the admission of air to the chamber 48, as described in detail hereinafter.

The primary mixture passages 44 connect in the wall of the main housing closely adjacent and substantially parallel to the vertical part 46 of the primary mixture passage with which it is associated. Each passage 40 is provided at its lower end with a small fuel feeding orifice 50, which supplies fuel to the primary mixture passage for idling and other low speed operations. At its upper end, each passage 40"communicateswith a horizontal passage 52, bored in the wall of the main housing a short distance above the orifice 50 and having its outer end closed by a plug 54. The diameter of the passage 52, where it communicates with the passage 40, is appreciably greater than that of the latter and is provided with a restricted outlet 56, which communicates with the vertical portion 46 of the primary mixture passage and constitutes a main fuel feeding orifice therefor. The orifice 56 is ineffective to supply fuel at low speeds, but comes into operation at intermediate speeds to augment the flow of fuel from the orifice 50 and remains effective during operations at all speeds hi gher than that at which it first begins to sup- Bored in the wall of the main housing are three passages 58 connecting with the passages 52 and with the main air chamber 46 to communicate the suction of said air chamber to the passage 52.

The passages 58 are' considerably larger than the fuel feeding orifice 56 and in view of this fact, the suction which is effective at any engine speed to lift fuel from the fuel bowl through the metering plugs 30 and 38 to the fuel feeding orifices 50 and 56, is substantially the static suction maintained in the air chamber 48 rather than that maintained in the primary mixture passages, which is dependent primarily on the velocity of flow through such passages, as fully explained in the copending application above referred to.

The flow of primary fuel mixture through the mixture passages 42 is controlled by means of a single primary throttle valve 60, which extends across passages 44 and is provided with grooves 62, each of which registers with one of said passages, as indicated in the drawings. This throttle is journalled in a suitable recess of all of the horizontal neath the flange 78, asshown in Fig. 1.

the same diameter as the throttle bored in the bottom wall of the main housing 10 and is operated by a mechanism fully described in the above mentioned application, but which is not material so far as the present invention is concerned. The primary mixture passages connect at their posterior ends with conduits formed in the-manifold wall, which convey the primary mixture to secondary mixing chambers formed in the manifold where it is 1 mixed with additional or secondary air during the operation of the engineat intermediate or high engine speeds. These conduits are fully disclosed in the above entitled application.

All of the air admitted to either primary or secondary mixing chambers," except the very small quantity of air which is admitted when the choke lever is operated to facilitate starting in the manner disclosed in the above application, enters the carburetors through an air inlet coupling 64, secured in a suit-' able opening in the housing by screws 66. The coupling is provided with a restricted throat 68 at the'apex of two conical surfaces 70 and 72, the surface 72 forming the seat for an air valve 74, which controls the admis- When it is desired to start the engine, the choke lever is operated by means disclosed in the above application, so as to lift the sleeve 80.into engagement with the valve 74 to hold the latter closed duringthe starting 1 of the engine, as fully described in the abovementioned application.

To preventfiuttering of the air valve and to retard its movement toward open position for the purpose of improving the operation during the acceleration period, a dashpot is provided which includes a cylinder 90 positioned within the fuel bowl and formed in the frame 14.. Received within the cylinder is a piston 92, which is mounted on the lower end of the air valve stem in any desirable way. This cylinder may be mounted on the valve stem in the manner disclosed in the above application or it may be secured thereto in anyconventional manner so far as the present invention is concerned. 1 The bottom of the cylinder is closed by a ,cap 94, S01- dered or'otherwise secured to .the frame 14 and in the center of this cap is a valve cage 96 in which a check valve 98 is received.

" This check valve is arranged to, permit flow into the cylinder 90 on closing movement of,

the air valve, but prevents escape of fuel from the cylinder on opening movement of the valve so that the dashpot operates to-re- .tard such openin'g movement.

Durmg operation at all engine speeds be-' low that corresponding to 'a vehicular speed of 20 to 25 miles per hour on the level, all of the air entering the intake ports passes through the primary mixture passages, the

mixture formed therein being of proper combustible proportions and of the desired quantity to properlyoperate the engine. At 3 speeds in excess of the above, however, additional air is admitted to the manifold to provide a sufiicient quantity of mixture and to supply this air, a secondary air passage 100, connecting the air chamber 48 and the manifold, is provided. The flow of air through the passage 100 is controlled by two valves, a manually operable throttle 1'02, se-

cured to an; operating shaft'104. and a suction operated valve 106, secured to a shaft .108, the shaits 104 and. 108 being rotatably I mounted in the main housing.- The operat- 5 ing connections 'for these two valvesconsti tute no part of the present invention and will not be described in detail herein, it he ing sufficient for the purpose of this disclo sure to describe very-briefly the mode of opa eration of these valves. 7 The primary throttle is connected to the valve'102 by a lost motion connection which permits a predetermined movement of the primary throttle independent of the valve 102. Such connection is capable of adjustment and is general.- ly adjusted so that the primary throttle may be moved without accompanying movement of the valve 102 until the "former reaches a. position corresponding to a vehicular speed of approximately 20 to 25 miles-per hour on a level. On further opening of the primary throttle, the valve 102 is moved simultaneouslytherewith, and the suction operated valve 106, which is pivoted oflf center, is adapt 11 ed to beopened by the'engine suction assoon as the valve 102 begins to open.-

Opening movement of the suction operated Valve 106 is retarded to aid in enriching the mixture for reasons fully set forth in 2%.."

the above application and in order to retard the opening of this valve, it has secured there to by brazing 'or in any other suitable way, an arm 110 which projects from its anterior face. This arm is connected pivotally to a Ii:.. t

short link 112 by a pin 114, and the link is pivotally connected by a pin 116 to acoupling member 118, which is screwed on therupper.

end of a piston rod '120. as shown in Fig. 1, and fully described in the above application. The piston rod is loosely received .within a v bore 122 in the bottom wall of the. main housing and pinned to the lower end of the rod is a sleeve 124,'-whi1e slidably'mo'unted on said sleeve is a dashpot piston 126, which fits through orifices to relieve the resistance ofv the dashpot. For this purpose, the piston is slidably mounted on the member 124 and is held in position against a flange 132, projecting from the piston rod 120, by a spring 134, which is received between the piston and a nut 136 on the upper end of the member 120. Under certain operating conditions, the resistance below the piston is. greater than the force exerted the piston lifts above the flange low fuel to pass through orifices 138 in the piston. So far as the present invention is concerned, however, the piston could be secured rigidly to the rod 120 and the dashpot by any conventional construction.

Heretofore, in devices of this character and in that disclosed in the prior application above referred to, aspring-has been provided below the piston 126 to return it toward normal position on any decrease in suction effective on the valve 106. It has been found diificult, however, to secure the desired operation of the piston on any change of suction and according to the present invention, the spring has been eliminated and means have been provided for moving the valve 106 toward closed position by the action of the engine suction. To this end, the piston rod 120 is provided with a fixed collar 140 at the point between the member 124 andthe bottom wall of the main housing. Engaging the under 132 to al side of this collar is a lever 142 pivoted at 144- in supporting members 146 depending from and integral with the wall of the main housing 10. The other endof this lever is pivotally connected to a short link148, the lower end of which is pivotally connected to a piston 150, slidably received in a cylinder 152, which is formed in the frame 14 and the wall of which extends to a point above the level of fuel in the fuel bowl. The lower end of the cylinder 152 is closed by a cap 154, secured thereto in any suitableway to prevent leakage. Communicating with the space below the piston 150 in the cylinder 152, is a suction passage comprising a tube 156 connected by any fluid-tight joint in the wall of the cylinder 152 and extending into abore 158 in the bottom wall of the main housing, as shown in Figs. 1 and 4, so that it communicates with the secondary air passage 100 through an orifice 160, situated immediately which are fully described.

by the spring 134 and secondary mixmg chamber,

in advance of or posterior to the manually operable valve 102 in said secondary air passa e.

The operation of this valve closing device will be obvious on inspection. manually operable throttle 102 is moved to closed position so that the suction effective on the valve 106 is decreased, the suction at points posterior to the valve 102 is increased. The increased suction is communicated through the tube 156 to the cylinder 152 below the piston 150, pulling the piston downwardly and raising the end of the lever 142 which engages the collar 140 to lift the piston rod 120 and move the valve 106 towards its closed position. Sincethe motion of the piston 150 is always dependent upon the engine suction and the position the valve 106 occupies is dependent upon the engine suction, it will be clear that the suction operated piston 150 is effective to move the valve 106 to the position it should properly occupy on any closing movement of the valve 102.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms. might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A charge forming device for internal combustion engines comprising a secondary mixing chamber, a primary mixing chamber for supplying a fuel and air mixture to said means for supplying fuel and air to said primary mixing chamber, a secondary air supply passage for supplying additional air to the secondary mixing chamber, a valve regulating the admission of air through saidsecondary air passage, and means operated by the suction in said secondary air passage for closing said valve.

2. A charge forming device for internal combustion engines comprising an intake passage, means for supplying fuel and air thereto to form a primary mixture, a seconda y air supply passage for supplying air to mix with said primary mixture, and air throttle in said secondary air passage, a valve in said secondary air passage for regulating the admission of air through said secondary air passage and adapted to be moved in one direction by the suction anterior to the throttle, and means operated by the suction posterior to the throttle for moving the valve in the other direction.

3. A charge forming device for internal combustion engines comprising an intake passage, means for supplying thereto to form a primary mixture, a secondary air supply passage for supplying air to mix with said primary mixture, an air throttie in said secondary air passage, a valve in said secondary air passage for regulating the admission of air through said secondary air When the fuel and air passage and adaptedto be opened by the sue tion maintained anterior to the throttl'eand means operated by the suction posterior to the throttle for moving the valve toward closed position.

4. A charge forming device for internal combustion engines comprising a primary mixture passage, means for supplyingfuel and air thereto, a secondary mixing chamber into which the primary mixture passage delivers a primary mixture of fuel and air, a secondary air supply passage admitting air to the secondary mixing chamber, a secondary air valve for controlling the flow therethrough, and means operated by the suction in said secondary air passage for closing said secondary air valve.

5. Acharge forming device for internal combustion engines comprising a primary mixture passage, means for supplying fuel and air thereto, a'secondary mixmgchamber into which the primary mixture passage delivers a primary mixture of fuel and air, a secondary air supply passage admitting air to the secondary mixing chamber, a secondary air valve for controlling the flow there--- through, and adapted to be opened by the suction maintained in one part of said secondary air passage, and means for closing said valve operated by the suction maintained in another part of said secondary air passage.

6., A charge forming device for internal combustion engines comprising a primary mixture passage, meansfor supplying fuel and air thereto, a secondary mixing chamber into which the primary mixture passage de livers a primary mixture of fuel and air, a secondary air supply passage admitting air to thesecondary mixing chamber, a second ary air valve for controlling the fiow therethrough, an air'throttle valve in said secondary passage and means operated by' the suctlOIl' in said passage posterior to the throttle for closing the secondary air valve.

7. A charge forming device for internal combustion engines comprising a primary m xture passage, means for supplying fuel and air thereto to form a primary mixture,

a secondary air supply passage for supplying air to mix with said primary mixture, a secondary air valve for controlling the flow through said secondary air passage, a piston operatively connected to said secondary air valve so as to move said valve as the piston is moved, a pressure cylinder in which the piston is slidable and a suction passage con necting said cylinder with said secondary air passage at a point anterior to the point where the secondary air mixes with the pri mary mixture, whereby the suction in said air passage is effective to close said valve.

8. A charge forming device comprising an intake passage, means for sup lying fuel and air to said intake passage to fbrm a primary mixture, asecondary air supply passage for supplying air to mix with said primary mixture, a valve for regulating the admission of" air through said air supply passage, a piston operatively connected to said valve so as to move the valve as the piston is moved, a

pressure cylinder in which the piston is slidable and a suction passage connecting said cylinder with the said air supply passage at a .point anterior to the point where the secondary air mixes with the primary mixture.

9. A charge forming device comprisingan intake passage, means for suplying fuel and air to said intake passage to orm a primary mixture, a secondary air supply passage for supplying air to mix with said primary mixture, an air throttle in said secondary air supply passage, a valve for regulating the ad mission of air through said airsupplypassage,

a piston operatively connected to said valve so as to move the valve as the piston is moved,

and asuction passage connecting the cylinder with the said air supply passage on the high suction side of the throttle at a point anterior to the .point where thesecondaryair mixes with the primary mixture.

10. A charge forming device for internal combustion engines comprising a primary mixture passage, means for supplying fueland air thereto, a secondary mixing chamber into which the primary mixture passage delivers, a secondary airsupply passage for supplying air to said secondary mixing chamber, a secondary air valve for controlling the flow therethrough, an air throttle valve in said secondary air passage, a piston operatively connected to said secondary air valve so as to move said valve as the piston is moved, a pressure cylinder in which the piston is slidable and asuction passage connecting said cylinder with the secondary air passage erated by the engine suction for moving said'valve toward closed position.

12. A charge forming device for internal combustion engines comprising a plurality of secondarymixing chambers, a plurality of primary carburetors for supplying a primary mixture of fuel and air thereto, means admitting fuel and air to said primary carburetors, a single secondary air passage supplying air to all of said secondary mixing Chambers, a valve controlling passage of air through said passage, and means operated by the engine suction for moving said valve toward closed position.

13. A charge forming device for internal ice combustion engines comprising a plurality of secondary mixing chambers, means for supplying a primary mixture of air and fuel thereto, a single air passage supplying auxiliary! air to all of: said secondary mixing chambers, a valve adapted to be opened by engine suction, for controlling admission of air through said passage and means also operated by engine suction for moving said 1 valve toward closed position.

14. A charge forming device for internal combustion engines comprising a plurality of secondary mixing chambers, means for supplying a primary mixture of air and fuel thereto, a single air passage supplying auxiliar'y air to all of said secondary mixing chambers, a valve adapted to be opened by engine suction for controlling admission of air through said passage, a. manually operable throttle valve, and means operated by the suction posterior to said throttle valve for closing said suction opened valve.

15. A charge forming device for internal combustion engines comprising a plurality of secondary mixing chambers, means for supplying a primary mixture of air and fuel thereto, a single air passage supplying auxiliary air to all of said secondary mixing chambers, a valve adapted to be opened by 9 engine suction for controllingadmission of air through said passage, a manually oper able throttle valve, a piston operatively connected to said suction opened valve so as to move said valve as the iston is moved, a

pressure cylinder in whic the piston is slidable and a suction passage connecting said cylinder with the secondary air passage on the high suction side of said throttle valve.

16. A charge forming device for internal combustion engines comprising an intake passage, means for supplying fuel and air thereto, a valve regulating the admission of air to said intake passage and adapted to be opened by engine suction, a dashpot for retarding the opening movement of said valve including a rod connectin the valve with the movable element of the ashpot and means engaging said rod and operated by the engine suction or moving said valve toward closed position.

In testimony whereof I hereto afix my signature.

WILFORD H. TEETER. 

